1,720,962 research outputs found
Analisi statistica di dati provenienti da contesti ambientali I
No full textIl presente report consiste in un resoconto dell'attività svolta nell’anno solare 2022 nell’ambito del progetto PON “Ricerca e Innovazione” 2014-2020, con tematica Green (Azione IV.5 e Azione IV.6). Il rapporto tecnico è stato sviluppato in collaborazione con l’azienda TEKRA s.r.l., specializzata nell’ambito della raccolta dei rifiuti, con sedi dislocate sul territorio nazionale. L’indagine statistica descrittiva riguarda le spese sostenute dall’azienda nel 2021 per la manutenzione ordinaria e straordinaria degli automezzi operativi, adibiti al raccoglimento dei rifiuti differenziati, pulizia delle strade e trasporto nei siti di smaltimento
Analisi statistica di dati provenienti da contesti ambientali II
No full textIl presente rapporto tecnico è stato realizzato nell’ambito del progetto PON “Ricerca e Innovazione” 2014-2020, con tematica Green (Azione IV.5 e Azione IV.6), ed inoltre nell’ambito del tirocinio curriculare previsto nel percorso di Laurea Magistrale in Matematica. L’attività si sviluppa in collaborazione con l’azienda Tekra s.r.l., specializzata nell’ambito della raccolta dei rifiuti, con sedi dislocate sul territorio nazionale. Esso consiste in un resoconto circa lo studio delle spese
sostenute nell’anno solare 2020 dall’azienda, riguardo la manutenzione ordinaria e straordinaria degli automezzi operativi. L’indagine statistica descrittiva ha seguito l’impostazione del precedente report dal titolo “Analisi statistica di dati provenienti da contesti ambientali I”, con autori il Dott. Marco Capaldo e la Dott.ssa Serena Spina
Cumulative information generating function and generalized Gini functions
No full textWe introduce and study the cumulative information generating function, which
provides a unifying mathematical tool suitable to deal with classical and fractional
entropies based on the cumulative distribution function and on the survival function.
Specifically, after establishing its main properties and some bounds, we show that
it is a variability measure itself that extends the Gini mean semi-difference.
We also provide (i) an extension of such a measure, based on distortion functions,
and (ii) a weighted version based on a mixture distribution.
Furthermore, we explore some connections with the reliability of -out-of-
systems and with stress-strength models for multi-component systems.
Also, we address the problem of extending the cumulative information
generating function to higher dimensions
Mean distances and dependence structures for lifetimes of systems with shared components
Full text linkDistortion and copula functions represent powerful tools in the description of the reliability of some complex systems as functions of their components' reliability. On this aim we study several pairs of reliability systems with one or more shared components, in the case when their lifetimes are independent and identically distributed or independent but not identically distributed. We focus on the dependence that arises from sharing components, often described by Marshall-Olkin copulas, making use of some distance measures related to the Gini's mean difference and its new recent generalizations. A special role is played by a new distortion function related to the ROC curve
Generalized equilibrium distributions
No full textWe define the generalized equilibrium distribution, that is the equilibrium distribution of a random variable with support in . This concept allows us to prove a new probabilistic generalization of the Taylor's theorem. Then, the generalized equilibrium distribution of two ordered random variables is considered and a probabilistic analogue of the mean value theorem is proved. Results regarding distortion-based models and mean-median-mode relations are illustrated as well. Conditions for the unimodality of such distributions are obtained. We show that various stochastic orders and aging classes are preserved through the proposed equilibrium transformations. Further applications are provided in actuarial science, aiming to employ the new unimodal equilibrium distributions for some risks measures, such as Value-at-Risk and Conditional Tail Expectation
Generalized Gini's mean difference through distortions and copulas, and related minimizing problems
Full text linkGiven a random variable and considered a family of its possible distortions, we define two new measures of distance between and each its distortion. For these distance measures, which are extensions of the Gini's mean difference, conditions are determined for the existence of a minimum, or a maximum, within specific families of distortions, generalizing some results presented in the recent literature
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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